1. Field of Invention
The invention relates to a movable body safety system. More particularly, the invention relates to a movable body safety system which is suitable for determining whether a subject movable body is in a state where attention is required during moving, based on road surface projection information formed on a road surface by a light beam radiated by a movable body such as a vehicle.
2. Description of Related Art
A vehicle safety system which radiates a light beam visible to others on a road surface is generally known. An example of such a system is disclosed in Japanese Patent Laid-Open Publication No. 5-238307. When a vehicle radiates a light beam visible to others on a road surface during running, they can visually recognize an indication formed on the road surface by the light beam radiated by the vehicle. Thus, a person who sees the indication on the road surface formed by the light beam can recognize that the vehicle exists in the vicinity even if the person cannot see the vehicle itself. Therefore, this system can inform others of the existence of the vehicle, which can improve safety concerning vehicle running.
According to the aforementioned system, a person can recognize the existence of a vehicle by seeing an indication formed on a road surface by a light beam radiated by the vehicle, even if the person cannot see the vehicle itself. Thus, it is possible for the person to recognize that some kind of attention is required. However, particularly a driver of a vehicle, which is a movable body, has difficulty in determining a relation with another vehicle even when the driver sees the indication on the road surface formed by the light beam radiated by the other vehicle.